[giantrobot]

> In my humble opinion tests are great if and only if they are hermetic and fast. Unfortunately, the important things that can go wrong are usually the least testable.

Integration tests are hard. A lot of time it's because deployment is very seat of the pants. Even with tightly managed deployment the test environment needs to be representative of the production environment. Just setting that up is time consuming and expensive. Then actually doing tests where the test environment has useful amounts of instrumentation without major performance or behavioral penalties.